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From: "Darrick J. Wong" <djwong@us.ibm.com>
To: Andreas Dilger <adilger.kernel@dilger.ca>,
	Theodore Tso <tytso@mit.edu>,
	"Darrick J. Wong" <djwong@us.ibm.com>
Cc: Sunil Mushran <sunil.mushran@oracle.com>,
	Amir Goldstein <amir73il@gmail.com>,
	Andi Kleen <andi@firstfloor.org>, Mingming Cao <cmm@us.ibm.com>,
	Joel Becker <jlbec@evilplan.org>,
	linux-ext4@vger.kernel.org, Coly Li <colyli@gmail.com>
Subject: [PATCH 13/51] libext2fs: Create the block bitmap checksum
Date: Tue, 13 Dec 2011 17:14:42 -0800	[thread overview]
Message-ID: <20111214011442.20947.84890.stgit@elm3c44.beaverton.ibm.com> (raw)
In-Reply-To: <20111214011316.20947.13706.stgit@elm3c44.beaverton.ibm.com>

Provide a field in the block group descriptor to store block bitmap checksum,
and some helper functions to calculate and verify it.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
 lib/ext2fs/blknum.c     |   15 +++++++++++++++
 lib/ext2fs/csum.c       |   44 ++++++++++++++++++++++++++++++++++++++++++++
 lib/ext2fs/ext2_fs.h    |    3 +++
 lib/ext2fs/ext2fs.h     |    6 ++++++
 lib/ext2fs/rw_bitmaps.c |   16 ++++++++++++++++
 5 files changed, 84 insertions(+), 0 deletions(-)


diff --git a/lib/ext2fs/blknum.c b/lib/ext2fs/blknum.c
index 190242c..5770238 100644
--- a/lib/ext2fs/blknum.c
+++ b/lib/ext2fs/blknum.c
@@ -203,6 +203,21 @@ static struct ext4_group_desc *ext4fs_group_desc(ext2_filsys fs,
 }
 
 /*
+ * Return the block bitmap checksum of a group
+ */
+__u32 ext2fs_block_bitmap_checksum(ext2_filsys fs, dgrp_t group)
+{
+	struct ext4_group_desc *gdp;
+	__u32 csum;
+
+	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
+	csum = gdp->bg_block_bitmap_csum_lo;
+	if (fs->super->s_desc_size < EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
+		csum |= ((__u32)gdp->bg_block_bitmap_csum_hi << 16);
+	return csum;
+}
+
+/*
  * Return the block bitmap block of a group
  */
 blk64_t ext2fs_block_bitmap_loc(ext2_filsys fs, dgrp_t group)
diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c
index 47c1111..1bad35c 100644
--- a/lib/ext2fs/csum.c
+++ b/lib/ext2fs/csum.c
@@ -74,6 +74,50 @@ errcode_t ext2fs_inode_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
 	return 0;
 }
 
+int ext2fs_block_bitmap_csum_verify(ext2_filsys fs, dgrp_t group,
+				    char *bitmap, int size)
+{
+	struct ext4_group_desc *gdp = (struct ext4_group_desc *)
+			ext2fs_group_desc(fs, fs->group_desc, group);
+	__u32 provided, calculated;
+
+	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+	provided = gdp->bg_block_bitmap_csum_lo;
+	calculated = ext2fs_crc32c_le(~0, fs->super->s_uuid,
+				      sizeof(fs->super->s_uuid));
+	calculated = ext2fs_crc32c_le(calculated, (unsigned char *)bitmap,
+				      size);
+	if (fs->super->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
+		provided |= (__u32)gdp->bg_block_bitmap_csum_hi << 16;
+	else
+		calculated &= 0xFFFF;
+
+	return provided == calculated;
+}
+
+errcode_t ext2fs_block_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
+				       char *bitmap, int size)
+{
+	__u32 crc;
+	struct ext4_group_desc *gdp = (struct ext4_group_desc *)
+			ext2fs_group_desc(fs, fs->group_desc, group);
+
+	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 0;
+
+	crc = ext2fs_crc32c_le(~0, fs->super->s_uuid,
+			       sizeof(fs->super->s_uuid));
+	crc = ext2fs_crc32c_le(crc, (unsigned char *)bitmap, size);
+	gdp->bg_block_bitmap_csum_lo = crc & 0xFFFF;
+	if (fs->super->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
+		gdp->bg_block_bitmap_csum_hi = crc >> 16;
+
+	return 0;
+}
+
 static errcode_t ext2fs_inode_csum(ext2_filsys fs, ext2_ino_t inum,
 			       struct ext2_inode_large *inode,
 			       __u32 *crc, int has_hi)
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index 70b9fa2..734e22d 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -194,6 +194,9 @@ struct ext4_group_desc
 #define EXT4_BG_INODE_BITMAP_CSUM_HI_LOCATION	\
 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
 	 sizeof(__u16))
+#define EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION	\
+	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
+	 sizeof(__u16))
 
 #define EXT2_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not initialized */
 #define EXT2_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not initialized */
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 3a07f4a..05f3e4c 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -798,6 +798,7 @@ extern errcode_t ext2fs_get_block_bitmap_range2(ext2fs_block_bitmap bmap,
 
 /* blknum.c */
 extern __u32 ext2fs_inode_bitmap_checksum(ext2_filsys fs, dgrp_t group);
+extern __u32 ext2fs_block_bitmap_checksum(ext2_filsys fs, dgrp_t group);
 extern dgrp_t ext2fs_group_of_blk2(ext2_filsys fs, blk64_t);
 extern blk64_t ext2fs_group_first_block2(ext2_filsys fs, dgrp_t group);
 extern blk64_t ext2fs_group_last_block2(ext2_filsys fs, dgrp_t group);
@@ -825,6 +826,7 @@ extern void ext2fs_free_blocks_count_add(struct ext2_super_block *super,
 extern struct ext2_group_desc *ext2fs_group_desc(ext2_filsys fs,
 					  struct opaque_ext2_group_desc *gdp,
 					  dgrp_t group);
+extern blk64_t ext2fs_block_bitmap_csum(ext2_filsys fs, dgrp_t group);
 extern blk64_t ext2fs_block_bitmap_loc(ext2_filsys fs, dgrp_t group);
 extern void ext2fs_block_bitmap_loc_set(ext2_filsys fs, dgrp_t group,
 					blk64_t blk);
@@ -938,6 +940,10 @@ extern __u32 ext2fs_crc32c_be(__u32 crc, unsigned char const *p, size_t len);
 extern __u32 ext2fs_crc32c_le(__u32 crc, unsigned char const *p, size_t len);
 
 /* csum.c */
+extern errcode_t ext2fs_block_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
+					      char *bitmap, int size);
+extern int ext2fs_block_bitmap_csum_verify(ext2_filsys fs, dgrp_t group,
+					   char *bitmap, int size);
 extern errcode_t ext2fs_inode_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
 					      char *bitmap, int size);
 extern int ext2fs_inode_bitmap_csum_verify(ext2_filsys fs, dgrp_t group,
diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c
index 0ad5eb1..a5097c1 100644
--- a/lib/ext2fs/rw_bitmaps.c
+++ b/lib/ext2fs/rw_bitmaps.c
@@ -92,6 +92,13 @@ static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 				for (j = nbits; j < fs->blocksize * 8; j++)
 					ext2fs_set_bit(j, block_buf);
 		}
+
+		retval = ext2fs_block_bitmap_csum_set(fs, i, block_buf,
+						      block_nbytes);
+		if (retval)
+			return retval;
+		ext2fs_group_desc_csum_set(fs, i);
+
 		blk = ext2fs_block_bitmap_loc(fs, i);
 		if (blk) {
 			retval = io_channel_write_blk64(fs->io, blk, 1,
@@ -272,6 +279,15 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 					retval = EXT2_ET_BLOCK_BITMAP_READ;
 					goto cleanup;
 				}
+				/* verify block bitmap checksum */
+				if (!(fs->flags &
+				      EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+				    !ext2fs_block_bitmap_csum_verify(fs, i,
+						block_bitmap, block_nbytes)) {
+					retval =
+					EXT2_ET_BLOCK_BITMAP_READ;
+					goto cleanup;
+				}
 			} else
 				memset(block_bitmap, 0, block_nbytes);
 			cnt = block_nbytes << 3;


  parent reply	other threads:[~2011-12-14  1:14 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-14  1:13 [PATCH v2.2 00/51] e2fsprogs: Add metadata checksumming Darrick J. Wong
2011-12-14  1:13 ` [PATCH 01/51] libext2fs: Read and write full size inodes Darrick J. Wong
     [not found]   ` <15FBE485-FC42-46A4-A2BE-9931A3B933A5@dilger.ca>
2011-12-19 17:46     ` Darrick J. Wong
2011-12-14  1:13 ` [PATCH 02/51] libext2fs: Change ext4 on-disk layout to support metadata checksumming Darrick J. Wong
     [not found]   ` <BBB7550D-77E9-441D-8ECF-C5A5A3B839C8@dilger.ca>
2011-12-19 20:13     ` Darrick J. Wong
2011-12-14  1:13 ` [PATCH 03/51] debugfs: Optionally ignore bad checksums Darrick J. Wong
2011-12-14  1:13 ` [PATCH 04/51] libext2fs: Add inode checksum support Darrick J. Wong
     [not found]   ` <4CD3617E-A647-4CAF-9C35-DF24656CB440@dilger.ca>
2011-12-19 20:05     ` Darrick J. Wong
2011-12-14  1:13 ` [PATCH 05/51] debugfs: Dump inode checksum when appropriate Darrick J. Wong
2011-12-14  1:13 ` [PATCH 06/51] tune2fs: Add inode checksum support Darrick J. Wong
2011-12-14  1:14 ` [PATCH 07/51] e2fsck: Verify and correct inode checksums Darrick J. Wong
     [not found]   ` <701CAD1A-51A8-4F0F-8323-4B2091BF8F78@dilger.ca>
2011-12-19 20:12     ` Darrick J. Wong
2011-12-14  1:14 ` [PATCH 08/51] mke2fs: Allow metadata checksums to be turned on at mkfs time Darrick J. Wong
     [not found]   ` <76441870-91E6-402F-B1F7-F67C97D0B02B@dilger.ca>
2011-12-19 16:59     ` Darrick J. Wong
2011-12-14  1:14 ` [PATCH 09/51] libext2fs: Create the inode bitmap checksum Darrick J. Wong
     [not found]   ` <8D63B0B0-ED5C-426E-82FE-5122A84DFFEC@gmail.com>
2011-12-19 20:03     ` Darrick J. Wong
2011-12-14  1:14 ` [PATCH 10/51] tune2fs: Rewrite inode bitmap checksums Darrick J. Wong
2011-12-14  1:14 ` [PATCH 11/51] dumpe2fs: Display inode bitmap checksum Darrick J. Wong
2011-12-18 18:09   ` Andreas Dilger
2011-12-14  1:14 ` [PATCH 12/51] e2fsck: Verify " Darrick J. Wong
2011-12-14  1:14 ` Darrick J. Wong [this message]
2011-12-14  1:14 ` [PATCH 14/51] dumpe2fs: Display block " Darrick J. Wong
     [not found]   ` <32C86905-38C6-4897-8A98-26431DB73118@dilger.ca>
2011-12-19 19:50     ` Darrick J. Wong
2011-12-14  1:14 ` [PATCH 15/51] e2fsck: Verify " Darrick J. Wong
2011-12-14  1:15 ` [PATCH 16/51] e2fsck: Don't verify bitmap checksums Darrick J. Wong
2011-12-14  1:15 ` [PATCH 17/51] tune2fs: Rewrite block " Darrick J. Wong
2011-12-14  1:15 ` [PATCH 18/51] libext2fs: Verify and calculate extent tree block checksums Darrick J. Wong
2011-12-14  1:15 ` [PATCH 19/51] tune2fs: Enable extent tree checksums Darrick J. Wong
2011-12-14  1:15 ` [PATCH 20/51] e2fsck: Verify extent tree blocks and clear the bad ones Darrick J. Wong
2011-12-19  6:50   ` Andreas Dilger
2011-12-19 19:47     ` Darrick J. Wong
2011-12-14  1:15 ` [PATCH 21/51] debugfs: Print htree internal node checksums Darrick J. Wong
2011-12-14  1:15 ` [PATCH 22/51] libext2fs: Add dx_root/dx_node checksum calculation and verification helpers Darrick J. Wong
2011-12-14  1:15 ` [PATCH 23/51] e2fsck: Verify htree root/node checksums Darrick J. Wong
2011-12-19  6:57   ` Andreas Dilger
2011-12-19 19:46     ` Darrick J. Wong
2011-12-14  1:15 ` [PATCH 24/51] libext2fs: Introduce dir_entry_tail to provide checksums for directory leaf nodes Darrick J. Wong
2011-12-14  1:16 ` [PATCH 25/51] e2fsck: Check directory leaf block checksums Darrick J. Wong
2011-12-14  1:16 ` [PATCH 26/51] tune2fs: Rebuild and checksum directories when toggling metadata_csum or changing UUID Darrick J. Wong
2011-12-14  1:16 ` [PATCH 27/51] libext2fs: Verify and calculate extended attribute block checksums Darrick J. Wong
2011-12-14  1:16 ` [PATCH 28/51] e2fsck: Check " Darrick J. Wong
2011-12-14  1:16 ` [PATCH 29/51] tune2fs: Rewrite " Darrick J. Wong
2011-12-14  1:16 ` [PATCH 30/51] libext2fs: Calculate and verify superblock checksums Darrick J. Wong
2011-12-14  1:16 ` [PATCH 31/51] e2fsck: Handle superblock checksum errors gracefully Darrick J. Wong
2011-12-14  1:16 ` [PATCH 32/51] libext2fs: Use i_generation in inode-related metadata checksums Darrick J. Wong
2011-12-14  1:16 ` [PATCH 33/51] libext2fs: Record the checksum algorithm in use in the superblock Darrick J. Wong
2011-12-14  1:17 ` [PATCH 34/51] tune2fs: Store checksum algorithm type in superblock Darrick J. Wong
2011-12-14  1:17 ` [PATCH 35/51] mke2fs: Record the checksum algorithm in use in the superblock Darrick J. Wong
2011-12-14  1:17 ` [PATCH 36/51] libext2fs: Block group checksum should use metadata_csum algorithm (if feature flag set) Darrick J. Wong
2011-12-14  1:17 ` [PATCH 37/51] tune2fs: Rewrite block group checksums when changing bg_use_meta_csum feature Darrick J. Wong
2011-12-14  1:17 ` [PATCH 38/51] mke2fs: Warn if not enabling all the features that metadata_csum wants Darrick J. Wong
2011-12-14  1:17 ` [PATCH 39/51] libext2fs: Add checksum to MMP block Darrick J. Wong
2011-12-14  1:17 ` [PATCH 40/51] e2fsck: Verify and correct MMP checksum problems Darrick J. Wong
2011-12-14  1:17 ` [PATCH 41/51] tune2fs: Force MMP update when changing metadata_csum flag Darrick J. Wong
2011-12-14  1:17 ` [PATCH 42/51] libext2fs: Change on-disk journal layout to support metadata checksumming Darrick J. Wong
2011-12-14  1:18 ` [PATCH 43/51] libext2fs: Dump feature flags for jbd2 v2 checksums Darrick J. Wong
2011-12-14  1:18 ` [PATCH 44/51] e2fsck: Check journal superblock checksum prior to recovery Darrick J. Wong
2011-12-14  1:18 ` [PATCH 45/51] e2fsck: Check revoke block checksum during recovery Darrick J. Wong
2011-12-14  1:18 ` [PATCH 46/51] e2fsck: Check descriptor block checksum when recovering journal Darrick J. Wong
2011-12-14  1:18 ` [PATCH 47/51] e2fsck: Check commit block checksum during recovery Darrick J. Wong
2011-12-14  1:18 ` [PATCH 48/51] e2fsck: Verify data block checksums when recovering journal Darrick J. Wong
2011-12-14  1:18 ` [PATCH 49/51] libext2fs: Enable support for the metadata checksumming feature Darrick J. Wong
2011-12-14  1:18 ` [PATCH 50/51] libext2fs: Bring the CRC32c implementation up to date with the kernel implementation Darrick J. Wong
2011-12-14  1:18 ` [PATCH 51/51] e2fsck: Refactor crc32_be code Darrick J. Wong

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